The biggest reason for the cloud storage increase is mobile data capture. Camera-equipped smartphones and tablets are driving the need to store greater amounts of data outside internal device drives or desktop drives, Gartner stated. The firm also projected that average storage per household will grow from 464GB in 2011 to 3.3 terabytes in 2016.

Even with only 7% of personal data stored in the cloud today, that represents more than 329 exabytes, Garter said. That figure will soar to 4.1 zettabytes (a zettabyte is 1 trillion gigabytes) of data by 2016.

"Local storage will become further integrated with home networking, presenting opportunities for local storage providers to partner with home networking and automation service providers," Shalini Verma, principal research analyst at Gartner, wrote in the June report.

"Cloud storage will grow with the emergence of the personal cloud, which in turn will simplify the direct-to-cloud model, allowing users to directly store user-generated content in the cloud. As storage becomes a part of the personal cloud, it will become further commoditized. Therefore, online storage and sync companies need to have a strategic rethink about their future approach," she added.

Dropbox is inviting users to share their stories about how they're using the online services and awarding its 10 favorites 100GB of data capacity for life.